APPENDIX A GEOTECHNICAL REPORT

Transcription

1 The City of Winnipeg Bid Opportunity No Appendix A Template Version: C C Bldg LR APPENDIX A GEOTECHNICAL REPORT

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3 CH2MHI City of Winnipeg Brady Landfill Waste Composting Facility Geotechnical Investigation Table of Contents Introduction... 1 Background and Existing Information Field Program Subsurface Investigation Soil Stratigraphy Groundwater Conditions Geotechnical Recommendations Liners Leaf and Yard Waste Pad Foundations Shallow Footings Thickened Edge Slab Grade Supported Concrete Slabs Recommendations for Leachate Collection Tank Containment Ponds Excavations Foundation Concrete Closure... 9 List of Figures Figure 01 Test Hole Location Plan List of Appendices Appendix A Test Hole Logs September 2012 Our File No.: Page i

4 CH2MHI City of Winnipeg Brady Landfill Waste Composting Facility Geotechnical Investigation Introduction This report summarizes the results of the geotechnical investigation completed by TREK Geotechnical Inc. (TREK) for the Leaf and Yard Waste Composting Facility and Pilot Biosolids Composting Facility at the Brady Road Resource Management Facility in Winnipeg, Manitoba. The terms of reference for the investigation are included in our subconsultant agreement with CH2MHI that was effective June 15, The scope of work includes a sub-surface investigation, laboratory testing, and the provision of recommendations for the design and construction of foundations, liners and pavements. Background and Existing Information The proposed facility will consist of the following components: Leaf and Yard Waste Pad: This will be a clay lined pad for storage and windrowing of leaf and yard waste. The pad is required to support daily truck traffic and loaders for moving materials on-site. A m thick compacted clay liner is proposed below the traffic pad. Various surface treatments options for the top of the pad are under consideration including: wood chips only, lean mix concrete, or a cement stabilized pad. Pond in Wetlands Area: A relatively shallow pond (about 4 m deep) will be developed in the proposed wetlands area located immediately south east of the site. This area will also be used as a borrow source for imported clay fill for the project. Aerated Static Pile Bunkers: This area will consist of a concrete slab on-grade. Dry stack retaining walls e.g. Lock-Block will be placed at several locations along the slab. At these locations the slab will be thickened to support the additional static load from the wall load. The slab will be subjected to loading by construction equipment such as loaders. Biofilter: The biofilter will be a large concrete slab with aeration pipes running through it at regularly spaced intervals. The pad will be subject to heavy equipment loading on an annual basis e.g. loader. Mixing and Receiving Building: This building will consist of a steel truss frame with a canvas cover. There will be a grade supported concrete floor slab throughout. Leachate Tank: A 2.4 m diameter by 7.5 m long tank will be installed at about 3 m below grade. All of the above components will be unheated. 3.0 Field Program 3.1 Subsurface Investigation A subsurface investigation was undertaken on June 27 to July 5, 2012 under the supervision of TREK personnel to determine the soil stratigraphy and groundwater conditions across the site. Test holes were drilled using a CME-850 track mounted drill rig equipped with 125 mm solid stem augers. Subsurface soils observed during the drilling were visually classified using the Unified Soil Classification System (USCS). Other pertinent information such as drilling, groundwater and backfill conditions were also recorded. Samples retrieved during drilling included disturbed grab samples, relatively undisturbed Shelby tubes, and disturbed split spoon samples; all samples were transported to TREK s testing laboratory in Winnipeg, Manitoba. Laboratory testing consisted September 2012 Page 1 Our File No.:

5 CH2MHI City of Winnipeg Brady Landfill Waste Composting Facility Geotechnical Investigation of moisture content determination on all samples. Atterberg limit, grain size analysis (hydrometer and mechanical), and undrained shear strength testing (pocket penetrometer, torvane and unconfined compression) testing was performed on select samples. A summary of the soil units encountered including laboratory testing results are included on the test hole logs in Appendix A. Thirty-four test holes (TH12-01 to TH12-34) were drilled at the locations shown on Figure 01. Thirty test holes were drilled to relatively shallow depth (between 3 and 5 m) to assess near surface conditions. Two test holes were drilled to 6 to 7 m depth (TH12-31 and TH12-32) to assess conditions below the future pond, and two test holes (TH12-29 and TH12-30) were advanced to power auger refusal to evaluate foundation conditions for the mixing and receiving building. Test hole logs are attached in Appendix A and include a description, the elevation of soil units encountered and other pertinent information such as groundwater levels and sloughing conditions. Test hole locations and elevations were surveyed by TREK personnel on July 5, The locations for test holes and could not be surveyed as the stakes used to identify the test hole locations had been removed by others. The approximate locations of these two test holes are shown on Figure Soil Stratigraphy The sub-surface stratigraphy in descending order from ground surface consists of: Fill/Organic (Topsoil) (Till) A brief description of the soil units are provided as follows: Fill / Organic (Topsoil) Either fill or organic clay was encountered in all test hole locations. The fill was encountered in TH12-14, TH12-15, TH12-16, TH12-20, TH12-21, TH12-22, TH12-23, and TH The fill extended from surface to a maximum depth of 1.8 m. The fill was generally variable and contained trace to some waste materials including refuse, wood, and compost. In some instances the fill was underlain by organic clay (topsoil). Organic clay (topsoil) was encountered at surface in all remaining test holes and extended to a maximum depth of 0.8 m. The organic clay is silty, contains some rootlets (<5 mm diam.), trace oxidation, trace silt inclusions (<2 mm diam.), is black to brown, dry to moist, stiff, with low to high plasticity. A silt layer ranging in thickness from 0.2 to 1.8 m was encountered in most test holes at depths ranging from 0.4 to 2.4 m from ground surface. A comparison of test hole logs indicates the silt layer across the site is highly variable in elevation, thickness and aerial extent. The silt generally contains some clay to clayey, trace sand, trace organics (rootlets < 1 mm diam.), trace oxidation, is medium brown, moist to wet, soft, and of low plasticity. Moisture contents range from 21% to 32%. September 2012 Page 2 Our File No.:

6 CH2MHI City of Winnipeg Brady Landfill Waste Composting Facility Geotechnical Investigation A clay layer underlies the fill and topsoil units to a maximum observed depth of 1 m in TH Near surface the clay is silty and contains trace organics, trace silt inclusions and is brown to grey, stiff, moist, and of high plasticity. With depth the clay transitioned to a grey colour and a soft to firm consistency. Moisture contents tended to increase with depth ranging from 26% to 64%. Bulk unit weights range from 16.2 to 17.4 kn/m 3. (Till) A silt till layer was encountered below the clay at a depths of 11.8 m and 1 m in TH12-29 and TH12-30 respectively. The silt till is sandy, contains trace to some gravel, trace clay, and is light grey. The upper 2.6 to 3.1 m of the till, referred to locally as putty till, is compact with moisture contents ranging from 9 % to 25 %, with an average of 13 %. The putty till is underlain by dense to very dense glacial silt till with moisture contents ranging from 6% to 8%. Power auger refusal in the dense till was reached at depths of 15.6 m and 15.7 m. Standard Penetration Tests (SPT) conducted in the dense silt till had blow counts of 60 (over 150 mm) and 100 (over 300 mm) at depths of 15.6 m and 15.7 m depth, respectively Groundwater Conditions Seepage, sloughing, and groundwater conditions observed during drilling are shown on the test hole logs. Seepage was observed on occasion from within near surface fill and silt layers and no seepage was encountered from the silt till unit. Standpipe piezometers were installed within the till layer in THs and to measure short term groundwater levels. Groundwater levels ranging from El m and were measured on July 25 and August 1, These observations are short term and should not be considered reflective of stabilized (static) groundwater levels. It is also important to note that groundwater conditions may change seasonally, annually, or as a result of construction activities. 4.0 Geotechnical Recommendations 4.1 Liners liners are planned below all areas of the proposed facility. The clay liners will be constructed using imported clay fill from the proposed wetlands area being constructed immediately south east of the site. To assess the suitability of the imported clay for liner construction two test holes were drilled within the borrow area (TH12-33 and TH12-34). Atterberg limits and hydrometer grain size analyses were performed on two samples of the clay and pertinent results are summarized in Table 1 below. Table 1 - Summary of Atterberg Limits/Grain Size Analysis in TH12-34 Sample Moisture Content Liquid Limit Plastic Limit Content m 30% 58% 16% 54% m 49% 86% 24% 73% September 2012 Page 3 Our File No.:

7 CH2MHI City of Winnipeg Brady Landfill Waste Composting Facility Geotechnical Investigation Based on the engineering properties shown in Table 1, both samples are considered suitable for use in constructing a clay liner. Although not measured, it is anticipated that hydraulic conductivities of the compacted clay will be well below 1x10-7 cm/sec. fill will need to be chosen selectively to avoid surficial organic soils and the silt layer that was observed in both test holes. The following procedures should be followed for construction of the clay liner: 1. Organic and fill soils should be stripped prior to construction of the clay liner. Excavation should proceed in a way that limits disturbance to the subgrade soils, the subgrade should be protected from inundation, drying, and freezing conditions. The need to excavate the silt will depend on the elevation of the surface of the silt layer across the site relative to the design subgrade elevation and the final design grades. encountered within m of final grade should be excavated and replaced with compacted clay fill. A non-woven geotextile (Geotex 801 or equivalent) should be placed on top of any remaining silt prior to bridging with a layer of compacted clay fill. Depending on the consistency of the silt layer, it may be necessary to use light weight equipment for placing and compacting the initial bridging layer. subgrade that will be incorporated into the liner should be scarified to a depth of 0.3 m and recompacted to 95% of Standard Proctor Maximum Dry Density (SPMDD). If the liner will be supporting settlement sensitive structures the compaction requirement should be increased to 98% SPMDD. If the subgrade will not be incorporated into the clay liner scarification and compaction will not be required, in this case the subgrade should be protected from disturbance, inundation, drying and freezing. The subgrade should be proof-rolled with a fully loaded tandem truck or other equipment of similar weight to determine the location of any localized soft areas. Soft areas should be repaired and treated as per direction by a geotechnical engineer. 2. should be placed in loose lift thicknesses that do not exceed 200 mm and compacted to 95% of SPMDD at a moisture content within 2 % of optimum. If the liner will be supporting settlement sensitive structures the compaction requirement should be increased to 98% SPMDD. Based on the in-situ moisture contents of the clay soil which are expected to be well above optimum for compaction, drying will likely be required. Frozen clay or other deleterious material such as organics, silt, or refuse should not be used as fill. 3. Prior to placement of an additional clay lift, the upper 50 mm of the existing surface should be scarified to promote bonding between the clay fill layers. 4.2 Leaf and Yard Waste Pad The leaf and yard waste pad is to be constructed above a m thick compacted clay liner and will be subject to daily truck and construction equipment loading. The pad will be gravel surfaced although there has been some consideration of surface treatment to prevent migration of gravel into the compost material. In considering the above requirements TREK recommends that crushed limestone be used at the site. The recommended minimum cross section present in descending order from the final surface is provided in Table 2. September 2012 Page 4 Our File No.:

8 CH2MHI City of Winnipeg Brady Landfill Waste Composting Facility Geotechnical Investigation Table 2 Proposed Granular Section in Leaf and Yard Waste Pad Material Gradation Proposed 20 mm down mm 50 mm down mm 100 mm down mm * Crushed rock should meet specifications identified in CW3110 The following recommendations are provided for construction of the granular pad: 1. A non-woven geotextile (Geotex 801 or equivalent) should be placed on top of the clay fill subgrade prior to granular fill placement. To provide additional reinforcement to the granular section, a woven geotextile such as a Geotex 315ST (or equivalent) could be used in place of the non-woven geotextile. The geotextile should be placed according to manufacturer specifications. 2. All granular fill should be placed in 150 mm (compacted thickness) lifts. The granular fill should be compacted to 98% SPMDD. Fill should be placed in an unfrozen condition. 3. If a rougher travelling surface is acceptable for end-use, the 20 mm down may be replaced with 50 mm down crushed limestone. Surface treatments for the granular pad that have been discussed include lean mix concrete and cement stabilization. If a cement stabilized pad is selected, the layer of 20 mm down crushed limestone should be increased to 150 mm and mixed with a minimum 5% by weight of Normal Portland cement (type GU). The cement should be mixed uniformly with the crushed limestone prior to compaction to 98% SPMDD. The cement content may be reduced through the use of additives such as fly-ash however the exact mix would need to be optimized through a laboratory testing program to confirm that performance is not compromised. 4.3 Foundations Foundations are required to support the Mixing and Receiving building. It is our understanding that the proposed building is a steel framed structure with canvas walls. The building will be unheated. Provided the building can tolerate some seasonal movement, shallow footings or a thickened edge slab are considered suitable at this site. If seasonal movements are not tolerable, TREK can provide recommendations on either end bearing or friction piles Shallow Footings Shallow footings founded below m depth on undisturbed in situ clay can be designed using an allowable bearing capacity of 80 kpa. The maximum settlement form this loading is expected to be 25 mm although shallow foundations may also be subject to additional vertical movement associated with seasonal shrinkage and swelling of the clay subgrade. Additional considerations for the design and construction of shallow footings are provided below: 1. Footings should have a minimum based width of 0.6 m. 2. Excavate to the design subgrade elevation while further ensuring that all fill soils and otherwise unsuitable material is removed. Excavation should be completed with a backhoe equipped with a smooth bladed September 2012 Page 5 Our File No.:

9 CH2MHI City of Winnipeg Brady Landfill Waste Composting Facility Geotechnical Investigation bucket operating from the edge of the excavation. Care should be taken not to over-excavate and to minimize the subgrade disturbance at all times. 3. After excavation, the subgrade should be reviewed by qualified geotechnical personnel. The exposed subgrade surface should be protected from freezing, inundation and disturbance. As such, it may be necessary for the contractor to sequence construction so that only a small portion of the subgrade remains open at a given time and that excavations are backfilled as soon as possible. 4. Where soft or weak areas are identified by the geotechnical personnel, these areas should be repaired as directed by the geotechnical engineer. If silt is encountered at the foundation elevation the geotechnical engineer should be notified immediately so that a remediation design can be provided. 5. Fill required to raise grades or for levelling should consist of 20 mm down crushed limestone placed in maximum 150 mm thick lifts and compacted to 98% SPMDD. 6. Grade supported structures such as floor slabs should be isolated from the footings to limit differential stresses Thickened Edge Slab A thickened edge slab could also be considered appropriate to support the Mixing and Receiving building. An allowable bearing capacity of 80 kpa should be used for design. In addition to the movements described in Section the thickened edge slab would also be subject to movements associated with freeze/thaw (frost heave) and settlement of any fill soils, such as the compacted clay liner, placed below the thickened edge. To minimize the effects of frost heave, near surface silts should be excavated from below the base of the thickened edge, frost heave can be further minimized by insulating the footings. TREK can provide design recommendations for insulation on request. For clay and crushed limestone compacted to 98% SPMDD settlements of up to 2% and % respectively of the layer thickness can be anticipated. Additional considerations for the design and construction of the thickened edge are provided below. Specific recommendations for design and construction of grade supported floor slabs can be found in Section Thickened edges should have a minimum based width of 0.6 m. 2. Excavate to the design subgrade elevation while further ensuring that all organics, silts, and un-compacted fill soils and otherwise unsuitable material is removed. Excavation should be completed with a backhoe equipped with a smooth bladed bucket operating from the edge of the excavation. Care should be taken not to over-excavate and to minimize the subgrade disturbance at all times. It is anticipated that the subgrade below the thickened edge will consist of either the compacted clay liner or compacted crushed rock. 3. After excavation, the subgrade should be reviewed by qualified geotechnical personnel. The exposed subgrade surface should be protected from freezing, inundation and disturbance. As such, it may be necessary for the contractor to sequence construction so that only a small portion of the subgrade remains open at a given time and that excavations are backfilled as soon as possible. 4. Where soft or weak areas are identified by the geotechnical personnel, these areas should be repaired as directed by the geotechnical engineer. 5. Fill required to raise grades or for levelling should consist of 20 mm down crushed limestone placed in maximum 150 mm thick lifts and compacted to 98% SPMDD. September 2012 Page 6 Our File No.:

10 CH2MHI City of Winnipeg Brady Landfill Waste Composting Facility Geotechnical Investigation If increased bearing capacity is required beneath the thickened edge, a compacted granular pad may be constructed below the base of the slab or thickened edge to distribute the contact load to maintain a bearing pressure of 80 kpa on the clay. In plan, the compacted granular pad should extend beyond the thickened edge by at least the gravel thickness. The allowable bearing pressure on the gravel pad can be calculated using the following formulae: q a = 80 (w+d)/w where: q a = allowable bearing pressure (kpa) w = width of thickened edge slab d = depth of gravel below thickened edge slab As an example, to accommodate an allowable load of 130 kpa on a 0.6 m wide thickened edge the granular pad would need to be 0.4 m thick, the granular pad would also need to extend at least 0.4 m beyond the thickened edge in all directions. The granular pad should be constructed using 50 mm down crushed limestone with the upper 100 mm of the granular pad constructed using 20 mm down crushed limestone as a levelling course. The crushed limestone should be compacted to a minimum of 98% SPMDD. Some settlement of the compacted granular fill should be expected as identified earlier in this section. 4.4 Grade Supported Concrete Slabs Grade supported concrete slabs will be subjected to loading from heavy construction equipment such as loaders. Some vertical deformation of grade supported slabs should be expected due to moisture and volume changes of the underlying soil, frost effects and settlement from underlying compacted fill soils. It is our understanding that the concrete slabs will be placed above the compacted clay liner discussed in Section 4.1. The following recommendations are provided to reduce or accommodate potential movements of the slab: 1. The sub-grade should be unfrozen and free of any deleterious material such as organics, debris, etc. prior to placement of granular fill. 2. Precautions should be taken to prevent desiccation of the sub-grade during construction. If drying of the sub-grade occurs it should be dampened, scarified and re-compacted to a minimum of 98% SPMDD. 3. The floor slab should be placed on a granular pad constructed of 200 mm of 50 mm down crushed limestone underlying 100 mm of 20 mm down crushed limestone. The crushed limestone should be placed in lift thickness not exceeding 150 mm and compacted to 98% SPMDD. If there is a desire to increase the granular thickness to protect the clay liner this should be done by increasing the 50 mm down layer thickness. 4. To minimize changes in soil moisture beneath grade supported floor slabs, the discharge from roof leaders and run-off from exposed slabs should be directed away from the structures. 5. To accommodate slab movements, it may be desirable to provide control joints to reduce random cracking and isolation joints to separate the slab from other structure elements. Allowances should be made to accommodate vertical movements of light partitions, etc. bearing on the slab. 6. Consideration should be given to providing a sub-floor drainage system consisting of a perimeter weeping tile drain, as well as interior lateral drains for larger areas. September 2012 Page 7 Our File No.:

11 CH2MHI City of Winnipeg Brady Landfill Waste Composting Facility Geotechnical Investigation 4.5 Recommendations for Leachate Collection Tank It is understood that a buried leachate collection tank (2.4 m diameter x 7.5 m long) will be installed at a depth of at least 3 m below grade. The tank should be founded on undisturbed in situ clay soils. s, fills, or organic soils should be removed from below the base of the tank and replaced with 20 mm down crushed limestone compacted to 98% of SPMDD. The tank should be backfilled according to the manufacturer s specifications. The tank base should also be design to resist buoyancy forces assuming that backfill material becomes completely saturated. 4.6 Containment Ponds It is understood that a containment pond, located on the southeast corner of the site in the vicinity of TH12-33 and TH12-34 to a depth of no more than 4 m. The stratigraphy in the area of the ponds generally consists of topsoil overlying highly plastic lacustrine clay. was encountered in TH from to 1.8 m, and in TH from 1.3 to 2.2 m. The natural highly plastic clay soils at this site are extensive and may be suitable as a natural in situ liner depending on the level of containment required and regulatory compliance. Natural liners will require that the upper silt layer (where encountered) be excavated and replaced with a minimum of 1 m of compacted clay. We estimate that at depth, the hydraulic conductivity of the undisturbed clay to be 1x10-7 cm/s or less although higher values may occur near the surface where seasonal environmental effects may result in a more pervious stratum. Scarification of the upper 300 mm and compaction should therefore be carried out to minimize the effects of construction disturbance and any environmental effects such as fissuring. If an engineered liner is required for the pond it could consist of compacted clay or a synthetic material e.g. high density polyethylene (HDPE). soil from on-site excavations should be suitable for a compacted clay liner if broken up and recompacted in thin lifts. In this regard, loose lifts should not exceed 150 mm and the clay should be compacted to achieve a minimum of 95% of SPMDD. Recommendations for synthetic liner installation can be provided if requested. Ponds constructed with natural or engineered clay liners should have internal side slopes no steeper than 4H:1V for a maximum depth (measured from the dyke crest to the floor) of 4 m and 5H:1V for ponds up to a maximum depth of 5 m. Recommendations for ponds greater than 5 m depth can be provided if requested. Where applicable, external side slopes for dykes should be constructed no steeper than 4H:1V. Erosion is expected to be minimal for ponds less than 300 x 300 m in aerial extent with maximum side slopes of 4H:1V and with grass cover. Ponds great than 300 x 300 m in aerial extent should have flatter side slopes and/or be provided with stone armouring or rip rap. The recommended pond geometry is based on the ponds remaining full; flatter slopes may be required in rapid drawdown conditions. TREK should be contacted if this operating case is expected or if recommendations for acceptable rates of drawdown are needed. 4.7 Excavations Temporary excavations at the site should meet Workplace Health and Safety regulations. It may be necessary to excavate open excavation side slopes flatter than 1 horizontal to 1 vertical if saturated silts are encountered. 4.8 Foundation Concrete Based on local experience the degree of exposure for concrete subjected so sulphate attack in Winnipeg is classified as severe according to CSA A Sulphate resistant (CSA Type HS) cement is recommended for September 2012 Page 8 Our File No.:

12 CH2MHI City of Winnipeg Brady Landfill Waste Composting Facility Geotechnical Investigation all below grade concrete works or concrete in contact with soil. Accordingly, all concrete in contact with the native soil should be made with high sulphate-resistant cement (HS or HSb). Furthermore, the concrete should have a minimum specified 56 day compressive strength of 32 MPa and have a maximum water to cement ratio of 0.45 in accordance with CSA A Concrete which may be exposed to freezing and thawing should be adequately air entrained to improve freeze-thaw durability in accordance with this same standard. 5.0 Closure The geotechnical information provided in this report is in accordance with current engineering principles and practices (Standard of Practice). The findings of this report were based on information provided (field investigation, laboratory testing, geometries). Soil conditions are natural deposits that can be highly variable across a site. If subsurface conditions are different than the conditions previously encountered on-site or those presented here, we should be notified to adjust our findings if necessary. All information provided in this report is subject to our standard terms and conditions for engineering services, a copy of which is provided to each of our clients with the original scope of work or standard engineering services agreement. If these conditions are not attached, and you are not already in possession of such terms and conditions, contact our office and you will be promptly provided with a copy. September 2012 Page 9 Our File No.:

13 CH2MHI City of Winnipeg Brady Landfill Waste Composting Facility Geotechnical Investigation Figures September 2012 Our File No.:

14 FUTURE POND 100m x 25m TH12-11 ACCESS POINT BENCHMARK LEAF YARD AND WASTE PAD TH12-32 TH12-31 TH12-10 ~450m DRAINAGE DITCH TH12-12 TH12-01 TH12-09 TH12-14 TH12-02 ~600m TH12-08 TH12-13 TH12-03 TH12-24 TH12-07 TH12-04 TH12-15 TH12-23 TH12-06 TH12-16 TH12-05 TH12-22 ~200m TH12-34 TH12-17 TH12-21 TH12-18 DRAINAGE DITCH TH12-20 TH12-19 TH12-25 ~160m TH12-30 TH12-28 TH12-29 BIOSOLIDS COMPOST FACILITY TH12-27 ~550m ~250m TH12-26 PONDS SCALE : 1:4000 (279mmx432mm) 200m TH12-33

15 CH2MHI City of Winnipeg Brady Landfill Waste Composting Facility Geotechnical Investigation Appendix A Test Hole Logs September 2012 Our File No.:

16 EXANATION OF FIELD AND LABORATORY TESTING GENERAL NOTES 1. Classifications are based on the United Soil Classification System and include consistency, moisture, and color. Field descriptions have been modified to reflect results of laboratory tests where deemed appropriate. 2. Descriptions on these test hole logs apply only at the specific test hole locations and at the time the test holes were drilled. Variability of soil and groundwater conditions may exist between test hole locations. 3. When the following classification terms are used in this report or test hole logs, the primary and secondary soil fractions may be visually estimated. Major Divisions Coarse-Grained soils (More than half the material is larger than No. 200 sieve size) Fine-Grained soils (More than half the material is smaller than No. 200 sieve size) s (More than half of coarse fraction is larger than 4.75 mm) s (More than half of coarse fraction is smaller than 4.75 mm) s and s (Liquid limit less than 50) with fines s and s (Liquid limit greater than 50) Highly Organic Soils Clean gravel (Little or no fines) (Appreciable amount of fines) Clean sands (Little or no fines) s with fines (Appreciable amount of fines) USCS Classification GW GP GM GC SW SP SM SC ML CL OL MH CH OH Pt Symbols Typical Names Well-graded gravels, gravel-sand mixtures, little or no fines Poorly-graded gravels, gravel-sand mixtures, little or no fines y gravels, gravel-sand-silt mixtures ey gravels, gravel-sand-silt mixtures Well-graded sands, gravelly sands, little or no fines Poorly-graded sands, gravelly sands, little or no fines y sands, sand-silt mixtures ey sands, sand-clay mixtures Inorganic silts and very fine sands, rock floor, silty or clayey fine sands or clayey silts with slight plasticity Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean clays Organic silts and organic silty clays of low plasticity Inorganic silts, micaceous or distomaceous fine sandy or silty soils, organic silts Inorganic clays of high plasticity, fat clays Organic clays of medium to high plasticity, organic silts Peat and other highly organic soils Determine percentages of sand and gravel from grain size curve, depending on percentage of fines (fraction smaller than No. 200 sieve) coarse-grained soils are classified as follows: ASTICITY INDEX (%) Less than 5 percent... GW, GP, SW, SP More than 12 percent... GM, GC, SM, SC 6 to 12 percent... Borderline case4s requiring dual symbols* C = U Laboratory Classification Criteria D 60 D 10 2 ( D ) greater than 4; 30 C C = between 1 and 3 D 10 x D 60 Not meeting all gradation requirements for GW Atterberg limits below "A" line or P.I. less than 4 Atterberg limits above "A" line or P.I. greater than 7 Not meeting all gradation requirements for SW Atterberg limits above "A" line or P.I. greater than 7 Above "A" line with P.I. between 4 and 7 are borderline cases requiring use of dual symbols D ( D U = greater than 6; 30 ) 2 60 C C = between 1 and 3 D C 10 D 10 x D60 Atterberg limits below "A" line or P.I. less than 4 Plasticity chart for solid fraction with particles smaller than mm Above "A" line with P.I. between 4 and 7 are borderline cases requiring use of dual symbols OR CL-ML ML OL OR LIQUID LIMIT (%) CL Von Post Classification Limit Plasticity Chart CI CH "U" LINE MH OH Strong colour or odour, and often fibrous texture "A" LINE Material Particle Size Particle Size Material mm ASTM Sieve Sizes mm ASTM Sieve sizes > 300 > 12 in. 75 to in. to 12 in. Coarse 0 to 4.75 #10 to #4 Medium to 0 #40 to #10 Coarse 19 to 75 3/4 in. to 3 in. Fine to #200 to #40 Fine 4.75 to 19 #4 to 3/4 in. or < < #200 * Borderline classifications used for soils possessing characteristics of two groups are designated by combinations of groups symbols. For example; GW-GC, well-graded gravel-sand mixture with clay binder. Other Symbol Types Asphalt Bedrock (undifferentiated) Concrete Limestone Bedrock and Fill Cemented Shale Till Non-Cemented Shale Till

17 EXANATION OF FIELD AND LABORATORY TESTING PI SPT RQD Su VW SI LEGEND OF ABBREVIATIONS AND SYMBOLS Liquid Limit (%) Plastic Limit (%) Plasticity Index (%) Moisture Content (%) Standard Penetration Test Rock ality Designation Unconfined Compression Strength Vibrating Wire Piezometer Slope Inclinometer Water Level at Time of Drilling Water Level at End of Drilling Water Level After Drilling as Indicated on Test Hole Logs FRACTION OF SECONDARY SOIL CONSTITUENTS ARE BASED ON THE FOOWING TERMINOLOGY TERM and "y" or "ey" some trace EXAMES and CLAY clayey, silty some silt trace gravel PERCENTAGE 35 to 50 percent 20 to 35 percent 10 to 20 percent 1 to 10 percent TERMS DESCRIBING CONSISTENCY OR COMPACTION CONDITION The Standard Penetration Test blow count (N) of a non-cohesive soil can be related to compactness condition as follows: Descriptive Terms Very loose Loose Compact Dense Very dense Descriptive Terms < 4 4 to to to 50 > 50 The Standard Penetration Test blow count (N) of a cohesive soil can be related to its consistency as follows: Very soft Soft Firm Stiff Very stiff Hard Descriptive Terms Very soft Soft Firm Stiff Very stiff Hard (Blows/300 mm) (Blows/300 mm) < 2 2 to 4 4 to 8 8 to to 30 > 30 The undrained shear strength (Su) of a cohesive soil can be related to its consistency as follows: < to to to to 200 > 200

18 Test Hole TH12-01 Client: CH2MHI Location: UTM 14 N , E Ground : m Existing Ground Date Drilled: June 27, 2012 : ORGANIC CLAY (Topsoil) - silty, some rootlets (<5 mm diam.) - mottled black and grey SILT - trace clay, trace fine sand, trace organics (rootlets <1 mm diam.) - medium brown - moist to wet, soft - low plasticity CLAY - silty, trace oxidation - light grey G01 G02 G03 -silt inclusions (<5 mm diam.) below 1.8 m G04 -firm below 2.3 m G END OF TEST HOLE AT 3.1 m IN CLAY 1) Test hole was squeezing in at 0.6 m below ground surface. 2) Test hole was dry approximately 15 minutes after drilling and open to 0.6 m below ground surface. 3) Test hole was backfilled with cuttings to 0.3 m below ground surface. One bag of bentonite was used in the test hole from 0.3m to the surface.

19 Test Hole TH12-02 Client: CH2MHI Location: UTM 14 N , E Ground : m Existing Ground Date Drilled: June 27, 2012 : ORGANIC CLAY (Topsoil) - silty, some rootlets (<5 mm diam.), trace oxidation, trace silt inclusions (<2 mm diam.) - mottled black and grey - dry to moist, stiff, high plasticity CLAY - silty, trace silt inclusions (<2 mm diam.) trace oxidation - light grey G06 G07 G08 -firm below 2.3 m G END OF TEST HOLE AT 3.1 m IN CLAY 1) Test hole was squeezing in at 0.6 m below ground surface. 2) Test hole was dry approximately 15 minutes after drilling and open to 0.6 m below ground surface. 3) Test hole was backfilled with cuttings to 0.3 m below ground surface. One bag of bentonite was used in the test hole from 0.3 m to the surface. G10

20 Test Hole TH12-03 Client: CH2MHI Location: UTM 14 N , E Ground : m Existing Ground Date Drilled: June 27, 2012 : ORGANIC CLAY (Topsoil) - silty, some rootlets (<5 mm diam.) - mottled black and grey, high plasticity CLAY - silty, trace coarse sand, trace organics (rootlets <10 mm diam.) - medium grey G11 G SILT - some clay, trace fine sand, trace organics (rootlets <1 mm diam.) - medium brown - moist to wet, soft - low plasticity CLAY - silty, trace medium sand, trace precipitates - light grey G13 T14 G END OF TEST HOLE AT 3.1 m IN CLAY 1) Test hole was squeezing in at 1.2 m below ground surface. 2) Test hole was dry approximately 15 minutes after drilling and open to 1.2 m below ground surface. 3) Water level was m below ground approximately one day after drilling. 4) Test hole was backfilled with cuttings to 1.2 m below ground surface. One bag of bentonite was used in the test hole from 0.3 m to the surface.

21 Test Hole TH12-04 Client: CH2MHI Location: UTM 14 N , E Ground : m Existing Ground Date Drilled: June 27, 2012 : ORGANIC CLAY (Topsoil) - silty, some rootlets (<5 mm diam.) - mottled black and grey, high plasticity CLAY - silty, trace organics (rootlets <1 mm diam.), trace oxidation, trace silt inclusions (<10 mm diam.) - dark grey, moist, stiff,high plasticity SILT AND CLAY LAYERS - 3 clay layers mm thick - 2 silt layers l25 mm thick SILT - some clay, trace fine sand, trace organics (rootlets <1 mm diam.) - medium brown, dry, soft, low plasticity -moist below 1.1 m G16 G17 G18 G CLAY - silty, trace medium sand, trace precipitates - light grey G20 -firm below 2.3 m END OF TEST HOLE AT 3.1 m IN CLAY 1) Test hole was squeezing in at 0.6 m below ground surface. 2) Test hole was dry approximately 15 minutes after drilling and open to 0.6 m below ground surface. 3) Test hole was backfilled with cuttings to 1.2 m below ground surface. One bag of bentonite was used in the test hole from 0.3 m to the surface. G21

22 Test Hole TH12-05 Client: CH2MHI Location: UTM 14 N , E Ground : m Existing Ground Date Drilled: June 27, 2012 : ORGANIC CLAY (Topsoil) - silty, some rootlets (<5 mm diam.) - mottled black and grey - dry, stiff, high plasticity SILT - some clay, trace oxidation - medium brown - moist to wet, firm - low plasticity -soft below 0.6 m G22 G23 G CLAY - silty, trace medium sand, trace precipitates (<2 mm diam.) - light grey -firm below 2.3 m G END OF TEST HOLE AT 3.1 m IN CLAY 1) Test hole was squeezing in at 0.8 m below ground surface. 2) Test hole was dry approximately 1 day after drilling and open to 0.8 m below ground surface. 3) Test hole was backfilled with cuttings to 1.2 m below ground surface. One bag of bentonite was used in the test hole from 0.3 m to the surface. G26

23 Test Hole TH12-06 Client: CH2MHI Location: UTM 14 N , E Ground : m Existing Ground Date Drilled: June 27, 2012 : ORGANIC CLAY (Topsoil) - silty, some rootlets (<5 mm diam.), mottled black and grey, dry, stiff, high plasticity CLAY - silty, trace medium sand, trace precipitates (<2 mm diam.) - mottled grey and brown G27 G28 T29 -firm below 2.3 m G END OF TEST HOLE AT 3.1 m IN CLAY 1) Test hole was dry approximately 1 day after drilling and open to 3.1 m below ground surface. 2) Test hole was backfilled with cuttings to 1.2 m below ground surface. One bag of bentonite was used in the test hole from 0.3 m to the surface. G31

24 Test Hole TH12-07 Client: CH2MHI Location: UTM 14 N , E Ground : m Existing Ground Date Drilled: June 27, 2012 : ORGANIC CLAY (Topsoil) - silty, some rootlets (<5 mm diam.) - mottled black - dry, stiff - low plasticity G CLAY - silty, trace medium sand, trace precipitates (<2 mm diam.) - brown G33 -firm below 2.3 m G END OF TEST HOLE AT 3.1 m IN CLAY 1) Test hole was squeezing in at 1.7 m below ground surface. 2) Test hole was dry approximately 1 day after drilling and open to 1.7 m below ground surface. 3) Test hole was backfilled with cuttings to 1.2 m below ground surface. One bag of bentonite was used in the test hole from 0.3 m to the surface. G35

25 Test Hole TH12-08 Client: CH2MHI Location: UTM 14 N , E Ground : m Existing Ground Date Drilled: June 27, 2012 : ORGANIC CLAY (Topsoil) - silty, some rootlets (<5 mm diam.), mottled black and grey, moist, stiff, high plasticity CLAY - silty, trace medium sand - light grey G36 -trace precipitates (< 50 mm diam.) below 0.8 m G37 T38 -firm below 2.3 m -trace silt inclusions (<25 mm diam.) at m G END OF TEST HOLE AT 3.1 m IN CLAY 1) Test hole was squeezing in at 1.7 m below ground surface. 2) Test hole was dry approximately 15 minutes after drilling and open to 1.7 m below ground surface. 3) Test hole was backfilled with cuttings to 1.2 m below ground surface. One bag of bentonite was used in the test hole from 0.3 m to the surface. G40

26 Test Hole TH12-09 Client: CH2MHI Location: UTM 14 N , E Ground : m Existing Ground Date Drilled: June 27, 2012 : ORGANIC CLAY (Topsoil) - silty, some rootlets (<5 mm diam.) - mottled black and grey, high plasticity CLAY - silty, trace coarse sand, trace organics (rootlets <10 mm diam.) - dark grey - dry to moist, stiff - intermediate plasticity G41 G SILT - some clay, trace fine sand, trace organics (rootlets <1 mm diam.) - medium brown - moist, soft - low plasticity CLAY - silty, trace medium sand, trace precipitates - brown G42A G END OF TEST HOLE AT 3.1 m IN CLAY 1) Test hole was squeezing in at 1.1 m below ground surface. 2) Test hole was dry approximately 15 minutes after drilling and open to 1.1 m below ground surface. 3) Test hole was backfilled with cuttings to 1.2 m below ground surface. One bag of bentonite was used in the test hole from 0.3 m to the surface. G44

27 Test Hole TH12-10 Client: CH2MHI Location: UTM 14 N , E Ground : m Existing Ground Date Drilled: June 27, 2012 : ORGANIC CLAY (Topsoil) - silty, some rootlets (<5 mm diam.) - black, high plasticity CLAY - silty, trace coarse sand, trace organics (rootlets <10 mm diam.) - mottled brown and grey - dry to moist, very stiff G45 G46 -firm below 2.1 m T47 G END OF TEST HOLE AT 3.1 m IN CLAY 1) Test hole was squeezing in at 1.4 m below ground surface. 2) Test hole was dry approximately 15 minutes after drilling and open to 1.4 m below ground surface. 3) Test hole was backfilled with cuttings to 1.2 m below ground surface. One bag of bentonite was used in the test hole from 0.3 m to the surface. G49

28 Test Hole TH12-11 Client: CH2MHI Location: UTM 14 N , E Ground : Not Surveyed Date Drilled: June 27, 2012 : ORGANIC CLAY (Topsoil) - silty, some rootlets (<5 mm diam.), black, moist, stiff, low plasticity CLAY - silty, trace organics (rootlets <10 mm diam.), trace oxidation, trace silt inclusions (<5 mm diam.) - medium brown -increasing silt content and low plasticity from 1.1 to 1.2 m -trace medium sand, trace precipitates (<5 mm diam.), and mottled grey and brown below 1.2 m G50 G51 G52 G53 -firm below 2.3 m G END OF TEST HOLE AT 3.1 m IN CLAY 1) Test hole was squeezing in at 0.9 m below ground surface. 2) Test hole was dry approximately 15 minutes after drilling and open to 0.9 m below ground surface. 3) Test hole was backfilled with cuttings to 1.2 m below ground surface. One bag of bentonite was used in the test hole from 0.3 m to the surface. 4) Test hole location based off of GPS coordinates. G55

29 Test Hole TH12-12 Client: CH2MHI Location: UTM 14 N , E Ground : m Existing Ground Date Drilled: June 27, 2012 : ORGANIC CLAY (Topsoil) - silty, some rootlets (<5 mm diam.), mottled black and grey, moist, stiff, low plasticity CLAY - silty, trace organics (rootlets <10 mm diam.) - black - dry, stiff G56 -dark grey and moist below 1.1 m -trace precipitates below 1.2 m G57 T58 G END OF TEST HOLE AT 3.1 m IN CLAY 1) Test hole was squeezing in at m below ground surface. 2) Test hole was dry approximately 1 day after drilling and open to m below ground surface. 3) Test hole was backfilled with cuttings to 1.2 m below ground surface. One bag of bentonite was used in the test hole from 0.3 m to the surface. G60

30 Test Hole TH12-13 Client: CH2MHI Location: UTM 14 N , E Ground : m Existing Ground Date Drilled: June 28, 2012 : ORGANIC CLAY (Topsoil) - silty, trace coarse sand, some rootlets (<5 mm diam.) - dark grey, moist, stiff, low plasticity CLAY - silty, trace organics (rootlets <10 mm diam.), trace silt inclusions (<5 mm diam.) - mottled brown and grey G61 G62 G63 -firm below 2.3 m G END OF TEST HOLE AT 3.1 m IN CLAY 1) Test hole was squeezing in at m below ground surface. 2) Test hole was dry approximately 15 minutes after drilling and open to m below ground surface. 3) Test hole was backfilled with cuttings to 1.2 m below ground surface. One bag of bentonite was used in the test hole from 0.3 m to the surface. G65

31 Test Hole TH12-14 Client: CH2MHI Location: UTM 14 N , E Ground : m Existing Ground Date Drilled: June 28, 2012 : CLAY (Fill) - silty, trace to some sand, trace coarse gravel, trace rootlets (<5 mm diam.), trace oxidation, trace glass - mottled grey and brown - moist, firm G ORGANIC CLAY (Topsoil) - silty, some organics (rootlets <5 mm diam.), mottled black and grey, moist, stiff, high plasticity CLAY - silty, trace coarse sand, trace organics (rootlets <10 mm diam.) - dark grey G67 G68 G G END OF TEST HOLE AT 4.6 m IN CLAY 1) Test hole was squeezing in at 3.1 m below ground surface. 2) Test hole was dry approximately 15 minutes after drilling and open to 3.1 m below ground surface. 3) Test hole was backfilled with cuttings to 1.2 m below ground surface. One bag of bentonite was used in the test hole from 0.3 m to the surface. G71 G72

32 Test Hole TH12-15 Client: CH2MHI Location: UTM 14 N , E Ground : m Existing Ground Date Drilled: June 28, 2012 : CLAY (Fill) - silty, trace to some sand, trace coarse gravel, trace organics (rootlets <5 mm diam.), trace oxidation, trace glass - mottled grey and brown - moist, firm, high plasticity WOOD CLAY - silty, trace coarse sand, trace organics (rootlets <10 mm diam.) - dark grey G73 G SILT - some clay, trace fine sand, trace organics (rootlets <1 mm diam.), trace oxidation - medium brown - moist, firm - low plasticity CLAY - silty, trace medium sand, trace precipitates - brown G75 G END OF TEST HOLE AT 4.6 m IN CLAY 1) Test hole was squeezing in at 3.5 m below ground surface. 2) Test hole was dry approximately 15 minutes after drilling and open to 3.5 m below ground surface. 3) Test hole was backfilled with cuttings to 1.2 m below ground surface. One bag of bentonite was used in the test hole from 0.3 m to the surface. T77 G78

33 Test Hole TH12-16 Client: CH2MHI Location: UTM 14 N , E Ground : Not Surveyed Date Drilled: June 28, 2012 : CLAY (Fill) - silty, trace to some sand, trace coarse gravel, trace to some organics (roots <50 mm diam.), trace oxidation, trace glass - mottled grey and brown - moist, firm G79 ORGANIC CLAY (Topsoil) - silty, some rootlets (<5 mm diam.), mottled black and grey, moist, stiff, high plasticity CLAY - silty, trace organics (rootlets <10 mm diam.), trace oxidation, trace precipitates (<1 mm diam.) - black - dry to moist, stiff G80 G SILT - trace to some clay, trace fine sand, trace organics (rootlets <1 mm diam.), trace oxidation - medium brown - moist, firm, low plasticity CLAY - silty, trace medium sand, trace precipitates - brown END OF TEST HOLE AT 4.6 m IN CLAY 1) Test hole was squeezing in at 2.1 m below ground surface. 2) Test hole was dry approximately 15 minutes after drilling and open to 2.1 m below ground surface. 3) Test hole was backfilled with cuttings to 1.2 m below ground surface. One bag of bentonite was used in the test hole from 0.3 m to the surface. 4) Test hole location based off of GPS coordinates. G82 G83 G84

34 Test Hole TH12-17 Client: CH2MHI Location: UTM 14 N , E Ground : m Existing Ground Date Drilled: June 28, 2012 : ORGANIC CLAY (Topsoil) - silty, some rootlets (<5 mm diam.), black, dry moist, stiff, high plasticity CLAY - silty, trace organics (rootlets <10 mm diam.), trace oxidation, trace silt inclusions (<3 mm diam.), trace precipitates (<1 mm diam.) - mottled dark grey and brown G85 G86 T87 -firm below 2.3 m G END OF TEST HOLE AT 3.1 m IN CLAY 1) Test hole was squeezing in at 1.8 m below ground surface. 2) Test hole was dry approximately 15 minutes after drilling and open to 1.8 m below ground surface. 3) Test hole was backfilled with cuttings to 1.2 m below ground surface. One bag of bentonite was used in the test hole from 0.3 m to the surface.

35 Test Hole TH12-18 Client: CH2MHI Location: UTM 14 N , E Ground : m Existing Ground Date Drilled: June 28, 2012 : ORGANIC CLAY (Topsoil) - silty, some organics (rootlets <5 mm diam.) - mottled black and grey - dry to moist, stiff, high plasticity CLAY - silty, trace organics (rootlets <10 mm diam.), trace oxidation, trace precipitates (<1 mm diam.) - black - dry to moist, stiff G89 G CLAY - silty, trace fine sand, trace organics (rootlets <1 mm diam.), trace oxidation - medium brown, moist, soft, low plasticity CLAY - silty, trace medium sand, trace precipitates - brown G91 G firm below 2.9 m END OF TEST HOLE AT 3.1 m IN CLAY 1) Test hole was dry approximately 15 minutes after drilling and open to 3.1 m below ground surface. 2) Test hole was backfilled with cuttings to 1.2 m below ground surface. One bag of bentonite was used in the test hole from 0.3 m to the surface. G93